The spectral sensitivities of identified receptors and the function of retinal tiering in the principal eyes of a jumping spider
- 364 Downloads
The functional organisation of the central retina of the anterior median (AM) eyes of a jumping spider,Plexippus (Salticidae) is examined by anatomical, electrophysiological and optical methods. A model of the eye is derived from the data.
The anatomy of the AM eye is similar to that of salticid eyes described by Land (1969a) and Williams and McIntyre (1980). There are four tiers of receptors of which only the most proximal (Layer I) is a regular mosaic with rhabdoms designed to have light-guide properties. The receptor population of Layer I is homogeneous, whereas in Layers II–IV more than one receptor type can be considered to contribute to each layer.
Intracellular recordings from AM photoreceptors reveal only two spectral classes: green cells with peak responses at ca. 520 nm, and ultraviolet (UV) cells with peak responses at ca. 360 nm. ERGs from intact retinae exhibit similar peaks. Spectral sensitivities from pooled intracellular recordings from green cells and ERGs correspond reasonably closely. The comparison does not, therefore, support the possibility that the retina contains receptors with peak responses at longer wavelengths, although it does not exclude it.
Spectrally characterised cells were marked by the injection of Lucifer Yellow. From the results of 13 successful injections, (a) peripheral Layer I and peripheral and central Layer II cells are green receptors; (b) Layer IV cells are UV receptors. Central Layer I and Layer III receptors were not marked.
The chromatic aberration, focal length and other optical parameters of the corneal lens of the AM eye were measured directly. The lens functions essentially as a single-surface lens of refractive index 1.40, and, together with the curved interface between the anterior chamber of the eye and the receptor matrix, forms a telephoto system.
The spacing between receptor Layers I and IV is matched to the chromatic aberration of the eye; if green light from an object in front of the spider is focused on Layer I, UV light will be focused on Layer IV (and Layer III).
The distal ends of Layer I receptors form a staircase, those lying laterally being closer to Layer II than those lying medially. This staircase enables the spider to receive in-focus images from objects at distances between ca. 3 cm — ∞ in front of it. It is suggested that the scanning movements of the retinae described by Land (1969b) serve to sweep an image across the staircase so that it will be in focus on some part of Layer I, provided that the object is within that range of distances.
Retinal tiering (including the staircase of Layer I) compensates both for the chromatic aberration of the dioptrics of the eye and for its inability to accommodate.
KeywordsRetina Spectral Sensitivity Peak Response Intracellular Recording Central Layer
anterior median (eye)
Unable to display preview. Download preview PDF.
- Blest AD, Land MF (1977) The physiological optics ofDinopis subrufus L. Koch: a fish lens in a spider. Proc R Soc Lond [Biol] 196:197–222Google Scholar
- Blest AD, Williams DS, Kao L (1980) The posterior median eyes of the dinopid spiderMenneus. Cell Tissue Res 211:391–403Google Scholar
- Born M, Wolf E (1975) Principles of optics, 5th ed. Pergamon Press, OxfordGoogle Scholar
- Crane J (1949) Comparative biology of salticid spiders at Rancho Grande, Venezuela. IV. An analysis of display. Zoologica NY 34:159–214Google Scholar
- DeVoe RD (1975) Ultraviolet and green receptors in principal eyes of jumping spiders. J Gen Physiol 66:193–208Google Scholar
- Drees O (1952) Untersuchungen über die angeborenen Verhaltensweisen bei Springspinnen (Salticidae). Z Tierpsychol 9:169–209Google Scholar
- Eakin RM, Brandenburger J (1971) Fine structure of the eyes of jumping spiders. J Ultrastruct Res 37:618–663Google Scholar
- Forster L (1979) Visual mechanisms of hunting behaviour inTrite planiceps, a jumping spider (Araneae, Salticidae). NZ J Zool 6:79–83Google Scholar
- Galbraith W (1955) The optical measurement of depth. Q J Microsc Sci 96:285–288Google Scholar
- Hardie RC (1979) Electrophysiological analysis of fly retina. I Comparative properties of R1-6 and R7 and R8. J Comp Physiol 129:19–33Google Scholar
- Hardie RC, Duelli P (1978) Properties of single cells in posterior lateral eyes of jumping spiders. Z Naturforsch 33c:156–158Google Scholar
- Homann H (1928) Beiträge zur Physiologie der Spinnenaugen. Z Vergl Physiol 7:201–268Google Scholar
- Kirschfeld K, Snyder AW (1975) Waveguide mode effects, birefringence and dichroism in fly photoreceptors. In: Snyder AW, Menzel R (eds) Photoreceptor optics. Springer, Berlin Heidelberg New York, pp 56–77Google Scholar
- Land MF (1969a) Structure of the principal eyes of jumping spiders (Salticidae: Dendryphantinae) in relation to visual optics. J Exp Biol 51:443–470Google Scholar
- Land MF (1969b) Movements of the retinae of jumping spiders (Salticidae: Dendryphantinae) in response to visual stimuli. J Exp Biol 51:471–493Google Scholar
- Land MF (1971) Orientation of jumping spiders in the absence of visual feedback. J Exp Biol 54:119–140Google Scholar
- Land MF (1980) Optics and vision in invertebrates. In: Autrum H (ed) Comparative physiology and evolution of vision in invertebrates. Springer, Berlin Heidelberg New York (Handbook of sensory physiology, vol VII/6B, pp 471–592)Google Scholar
- Laughlin SB, Blest AD, Stowe S (1980) The sensitivity of receptors in the posterior median eye of the nocturnal spiderDinopis. J Comp Physiol 141:53–65Google Scholar
- Longhurst RS (1973) Geometrical and physical optics, 3rd ed. Longman, LondonGoogle Scholar
- Mandell RB (1967) Corneal contour of the human infant. Arch Ophthalmol 77:345–348Google Scholar
- Payne R (1980) Voltage noise accompanying chemically-induced depolarization of insect photoreceptors. Biophys Struct Mech 6:235–251Google Scholar
- Stewart WW (1978) Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthalimide tracer. Cell 14:741–759Google Scholar
- Williams DS (1979) The physiological optics of a nocturnal semi-aquatic spiderDolomedes aquaticus (Pisauridae). Z Naturforsch 34c:463–469Google Scholar
- Williams DS (1980) Ca+ +-induced structural changes in photoreceptor microvilli of Diptera. Cell Tissue Res 206:225–232Google Scholar
- Williams DS, McIntyre P (1980) The principal eyes of a jumping spider have a telephoto component. Nature 288:578–580Google Scholar
- Yamashita S, Tateda H (1976) Spectral sensitivities of jumping spider eyes. J Comp Physiol 105:1–8Google Scholar